Acute toxicity of diazinon is similar for eight stocks of bobwhite

Nine-week-old bobwhite (Colinus virginianus) from eight different game farms were tested for their sensitivity to an acute oral exposure of technical-grade diazinon (phosphorothioic acid O,O-diethyl-O-[6-methyl-2-(l-methylethyl) -4-pyrimidinyl]ester). Extraneous variables associated with interlaboratory differences in husbandry were eliminated by incubating eggs and rearing chicks to test age for all stocks simultaneously in the same facilities at the Patuxent Wildlife Research Center. Under this single set of conditions, the responses of the eight stocks of bobwhite to diazinon were statistically inseparable, with LD₅₀ values varying from 13 mg/kg (95% confidence interval, 8–21 mg/kg) to 17 mg/kg (95% confidence interval, 11–25 mg/kg). The pooled LD₅₀ for the eight stocks was 14.7 mg/kg (95% confidence interval, 13.1–16.5 mg/kg).